How much more does a 6% mortgage cost compared to 3%?

On a $300,000 loan over 30 years: 3% costs $155,400 in total interest while 6% costs $347,640. That's $192,240 more — nearly doubling your cost of borrowing. Monthly payments jump from $1,265 to $1,799, a $534/month increase.

Why are rates 6% now when they were 3% in 2021?

The Federal Reserve raised benchmark rates aggressively from March 2022 through 2023 to fight inflation. Mortgage rates follow the 10-year Treasury yield, which climbed from about 1.5% to 4.5%. Sub-3% rates in 2020-2021 were historically abnormal — the current 6%+ range is closer to the 50-year historical average.

Should I wait for rates to drop back to 3%?

Most housing economists don't expect rates to reach 3% again without another major economic disruption. The consensus forecast for 2026-2027 is 5.5%–6.5%. If home prices continue rising during your wait, you may end up paying more overall even with a lower rate on a higher purchase price.

Does doubling the mortgage rate double the interest cost?

More than doubles it. At $300,000 over 30 years: 3% generates $155,400 in interest while 6% generates $347,640. That's 2.24x the interest — not 2x — because of how compound interest works over long terms. The longer the loan and the higher the rate, the more this multiplier grows.

Rate Comparison Updated May 2026 9 min read

3% vs 6% Mortgage Interest — How Doubling the Rate More Than Doubles the Cost

If you locked in at 3% during the pandemic, you're sitting on gold. On a $300,000 mortgage, going from 3% to 6% adds $192,240 in total interest and $534/month to your payment. The rate doubled, but the interest cost more than doubled — it jumped from $155,400 to $347,640 (a 2.24x increase). If you locked in at 3% during 2020–2021, you're sitting on a genuinely valuable asset. If you're buying now at 6%, understanding what that rate costs — and how overpayments offset it — matters. Run your comparison here.

Monthly payment side by side: 3% vs 6%

Anyone who bought a home in 2020 or 2021 and locked sub-3% rates knows what cheap money looks like. Anyone buying in 2025–2026 at 6%+ is learning what normal historically looks like — and it feels expensive by comparison. Here's how the two rates stack up:

Loan Amount	3% (30yr)	6% (30yr)	Monthly Gap
$200,000	$843	$1,199	$356
$250,000	$1,054	$1,499	$445
$300,000	$1,265	$1,799	$534
$400,000	$1,686	$2,398	$712
$500,000	$2,108	$2,998	$890

At $300,000, you're paying $534 more per month. Over a year, that's $6,408. Over 30 years — well, that's where the total interest comparison comes in.

Total interest: this is where the gap becomes staggering

📊 Total interest paid — 3% vs 6% over 30 years

$200K at 3%$103,480 interest

$200K at 6%$231,640 interest — $128,160 more

$300K at 3%$155,400 interest

$300K at 6%$347,640 interest — $192,240 more

$500K at 3% vs 6%Gap: $320,400 in extra interest

On a half-million dollar loan, the interest gap between 3% and 6% is $320,400. That's not a typo. Three hundred and twenty thousand dollars. The difference would buy a nice house outright in most Midwest and Southern markets.

Will rates ever hit 3% again?

Probably not soon, and possibly not for a very long time. The 2.65%–3.25% rates of 2020–2021 were driven by pandemic-era Federal Reserve policy — near-zero fed funds rates combined with massive bond purchases. Those conditions were extraordinary.

Most economists and the Fed's own projections suggest a "neutral" long-term rate around 2.5–3.0% for the fed funds rate. That translates to mortgage rates of roughly 5–6%. Rates below 4% would likely require another severe economic downturn. Planning your homebuying timeline around a return to 3% mortgage rates isn't a strategy — it's a gamble on recession.

What 6% borrowers can actually do about it

Overpayments are the most effective tool. At 6% on a $300,000 loan, paying $200/month extra saves $86,800 and cuts 6.5 years off the loan. That doesn't bring your effective rate down to 3%, but it dramatically reduces your total interest — closing a meaningful portion of the gap. The $200/month savings breakdown quantifies this across loan sizes.

For different rate gaps, the 5% vs 6% comparison shows narrower spreads, and the 6% vs 7% guide covers the range most 2026 buyers are shopping in. The refinance vs overpay analysis helps if you're trying to decide between lowering your rate and making extra payments.

For historical rate data and forecasts, Freddie Mac's rate archive tracks weekly averages since 1971. The Federal Reserve's monetary policy page provides context on why rates moved and where policymakers expect them to go.

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3% vs 6% Mortgage — Questions

How much more does a 6% mortgage cost than 3%?

On $300,000 for 30 years: $192,240 more in total interest and $534/month more in payments. On $500,000: $320,400 more in interest and $890/month more. The gap scales roughly proportionally with loan size.

Should I keep my 3% mortgage or sell and rebuy?

A 3% mortgage is a financial asset. On a $300K loan, your rate saves you $534/month compared to 6%. That's $192,240 over the loan's life. Selling means giving that up. Most financial advisors recommend keeping sub-3.5% loans unless you absolutely must relocate.

Will mortgage rates drop to 3% again?

Unlikely without a severe economic disruption. Consensus forecasts for 2026–2027 are 5.5%–6.5%. Sub-3% rates required pandemic-era interventions — near-zero fed funds rates and massive Fed bond purchases — that are not expected to repeat.

Can overpayments close the gap between 3% and 6%?

Partially. On a $300K loan at 6%, paying $300/month extra saves $110,500 — covering 57% of the $192,240 gap vs a 3% loan. You can't fully replicate a 3% rate, but overpayments meaningfully reduce the total cost difference.

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Team OverpayCalc.com

We built OverpayCalc during the rate shock of 2023 — when millions of homeowners suddenly realized what "normal" mortgage rates look like. The goal: clear math, zero guesswork.

For illustration purposes. Rate comparisons use standard 30-year fixed amortization. Actual mortgage costs include taxes, insurance, and PMI not shown here. Current average rates sourced from Freddie Mac PMMS.